จำนวน Repository ( 3611 )

The Development of a Computer Assisted Instruction Package with Tutorial Through E-Learning on Computer Technology Curriculum
The Development of a Computer Assisted Instruction Package with Tutorial Through E-Learning on Computer Technology Curriculum

The purposes of the research were to design and develop a computer assisted instruction package with tutorial through e-learning on computer technology curriculum and to find out efficiency effectiveness and learners’ satisfaction towards the package. The research tools are 1) the Computer Instruction Package on Database Management System Subject 2) Achievement evaluations 3) Quality assessment and evaluation form for multimedia software and 4) Questionnaire of learners’ satisfaction. The research results reveals that the efficiency of the Computer Instruction Package was at 82.50/82.56 corresponding with 80/80 criteria. The analysis of pre-test and post-test scores finds that the effectiveness after the process (Epost) was at 82.56 which was higher than one tested before the process (Epre) which was at 14.62. Therefore the Computer Instruction Package on Program Design and Development could increase the students learning effectiveness up to 67.94 corresponding with 60 criteria. The Mean of satisfaction of the sampling groups was rather at a high level (4.28). It could be concluded that the Computer Assisted Instruction Package with tutorial through e-learning on computer technology curriculum had the efficiency that could used for self study.

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Influence of Electrode Force Affecting the Complete of the Resistance Spot Welding
Influence of Electrode Force Affecting the Complete of the Resistance Spot Welding

This research was to influence of electrode force affecting the complete of the resistance spot welding. The specimen was mild steel sheet metal has 1 mm. thickness. Then applied the force to the specimen are 1.0 2.0 3.0 4.0 and 5.0 kN. The welded specimens were tested by tensile shear testing according to JIS Z 3136: 1999 and Macro structure testing according to JIS Z 3139: 1978.The results showed that electrode force had affected on tensile shear and nugget size at 95% confidential (P value > 0.05). The low electrode force had increase the nugget heating because it had a high resistance (Q=I2Rt) and increase the gab between specimen. When the resistance increasing so the current flow will difficult to passed that fusion zone will had a high heating. It will affected to nugget seize heat affected zone and mechanical properties decreasing. The electrode forces are complete 2.0 kN. Tensile shear 6.39 kN and Nugget Size 5.83 mm. This data can be applied to be used as process monitoring of resistance spot weld quality.

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Mechanical Properties of Silica-Based Geopolymer Composites Cured at Ambient Conditions in Accordance with Size-Independent Method
Mechanical Properties of Silica-Based Geopolymer Composites Cured at Ambient Conditions in Accordance with Size-Independent Method

In this paper silica-based geopolymer matrix reinforced composites containing approximately 35 50 or 55 wt.% of carbon (HTS 5631 1600tex 24K TohoTenax) advanced basalt (BCF13-2520tex KV12 Int Basaltex) or electrical grade glass (E-glass: E2400P192 Saint-Gobain Vetrotex) roving fibers respectively were synthesized and fabricated at ambient conditions. The flexural properties of the resulting composites which are high toughness: the shear stress plays here a greater role in compared with other ceramic matrix composites were determined on a universal testing machine under three-point bending mode in accordance with novel size-independent method which based on testing specimens at different scale of sample height (H) to span length (L) ratios; The basic principles of the new size-independent approach are presented as well. Microstructures of composites were analyzed by means of scanning electron microscope (SEM) on perpendicular sections the images show the adhesion between the fibers and geopolymer matrix are very good and micro-cracks on both cross-sections and surfaces of geocomposites are determined as inborn defects of inorganic matrix composites.

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Temperature Reduction in Hydroponic Planting System Using Heat Pipe
Temperature Reduction in Hydroponic Planting System Using Heat Pipe

This paper presents an establishment of a mathematical model to determine the optimal size of heat pipe (thermosyphon) heat exchanger for reduce the inlet air temperature in evaporative cooling system of greenhouse. The condition of a mathematical model is the total length of heat pipe is 1.5 m. A mathematical model will determine the optimal value of evaporator section and condenser section. The range of evaporator length is 0.5 – 1.4 m with an increment of 0.1 m and condenser length is in range of 0.1 – 1.0 m with an increment of 0.1 m. The inlet air temperature in evaporative cooling of greenhouse is depend on ambient temperature about 35 degree Celsius. While the cooling water temperature is 20 degree Celsius. Evaporative pad of evaporative cooling system is 2 m in width and 7 m in length. From the conditions above the optimize results from a mathematical model are as follows: evaporator section length is 0.9 m and condenser section length is 0.6 m moreover it was shown that investment net saving and maximum heat rate are 79.83 Thousand Baht 0.552 Million Baht and 15.6 kW respectively.

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Contamination of Endocrine Disrupting Compounds in Environment
Contamination of Endocrine Disrupting Compounds in Environment

Endocrine disrupting compounds (EDCs) are the substances that disrupt normal functions of hormones produced by endocrine glands affecting to system and organism functions under hormone control altering from nature conditions consequently cause adverse health effect in human and other living organisms. Most EDCs characteristics are lypophilic and persistence in environment. The hazardous EDCs produce from human activities contaminating in environment such as water air soil and food are produced etc.

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